This invention relates to the art of moving fabric through a pre-selected processing step and apparatus for accomplishing this purpose is typically referred to as a tenter frame.
Normally, such a device includes a frame which serves to support a double chain and pin arrangement spaced from each other so that the edges of the fabric web may be placed on the pins in a desired fashion whereby any distortions in the fabric are minimal or eliminated.
More importantly, as the fabric is moved through the processing step or steps--and particularly as speed changes, stops and starts occur--it will be understood that this must be accomplished without any fabric distortion or other forms of fabric instability to speak of.
Improvements in the movement of fabric to minimize the above-mentioned distortions and the recurrence of instability have from time to time been made and are known in the prior art.
In particular, the significant gains made in computerization and the development of electronic and electrical improvements have provided--to a degree--various techniques to achieve the desired minimization of the damaging distortions in the fabric.
However, such electrical techniques have created a number of other deficiencies, such as the requirement to have available highly-skilled technical personnel to cope with breakdowns. Such equipment is also expensive, both from an operational and investment standpoint.
In electronic or electrical type systems--fabric quality is not maximized due to problems that may develop from the lag in response which generally occurs in this type system. This lag occurs particularly in systems which employ multiple motors which need to be synchronized.